Colorectal Surveillance in Lynch Syndrome: Variation by Affected Gene

Lynch syndrome is caused by mutation in one of the mismatch repair genes — MLH1, MSH2, MSH6, and PMS2. Individuals with Lynch syndrome are at markedly increased risk for CRC, and guidelines recommend screening colonoscopy at age 20 to 25 years followed by surveillance every 1 to 2 years. The risk for CRC varies depending on the gene involved, but guidelines are inconsistent with regard to mutation-specific recommendations.

Now, researchers report CRC outcomes in 381 patients with Lynch syndrome prospectively enrolled in New Zealand's national registry for familial gastrointestinal cancers. Patients had pathogenic variants in MLH1 (n=98), MSH2 (n=159), MSH6 (n=103), and PMS2 (n=21). During a median follow-up of 6.5 years, 18 CRCs were diagnos…